Process of making acid nitriles.



No. 778,656. Patented December 27, 1904.

UNITED STATES PATENT OFFICE.

OTTO J. GRAUL, OF LUDWIGSHAFEN-ON-THE-RHINE, GERMANY, ASSIGNOR TO BADISCHE ANILIN UND SODA FABRIK, OF LUDVVIGSHAFEN-ON-THE- RHINE, GERMANY, A CORPORATION OF BADEN.

PROCESS OF MAKING ACID NlTRILES.

SPECIFICATION forming part of Letters Patent No. 778,656, dated December 27, 1904.

Application filed December 22, 1903. Serial No. 186,216.

To all 1127mm 1'1 Hwy mw of the aromatic series, whereas R may indi- Be it known that I, OTTO J GRAUL, doctor cate a radical generally both aromatic and ali- 5 O of philosophy and chemist, a subject of the phatic, including the radicals of the aliphatic Duke of Anhalt, residing at Ludwigshafen-onseries OnH2n 1, in which expression n may 5 the-Rhine, in the Kingdom of Bavaria, Embe equal toOor any other number. The prepapire of Germany, have invented new and useration is effected according to my invention fulImprovementsin Processes of Manufacturby treating the said Schifi base after its for- 55 ing Acid Nitriles, of which the following is a mation with dilute aqueous or aqueous alcospecification. holic solutions of hydrocyanic acid, provided My invention relates to the manufacture of that an elevated temperature be employed. acid nitriles from the so-called Schiff bases The most favorable temperature for the purand hydrocyanic acid. IV. v. Miller and pose varies with different Schiff bases. In 60 Plochl have shown that the said Schiff bases some cases the temperature of the water-bath on treatment with concentrated or anhydrous is sufiicient, but in others a somewhat higher 5 hydrocyanic acid are converted into the nitemperature is necessary. It is preferable to triles, (Be/delete, Vol. XXV, page 2020; of. work in. closed vessels, as otherwise the hydroalso Beric/tm-Vol. VI, page 74:8, and Vol. XI, cyanic acid is liable to escape. N o specially 6 5 7 page 246.) Several attempts have been made energetic shaking of the materials is neces- F to improve this process. See, for instance, sary, and an ordinary vessel fitted with a stirthe specification of Letters Patent No. 718,340 rer is sufficient for use in the operation.

and also the specifications of English Letters My invention renders it possible while using Patents Nos. 21,077 of1901 and 24,461 of 1902. an ordinary dilute solution of hydrocyanic 7 The processes described in the specifications acid and a Schiff base powdered in the usual of these two English Letters Patent are based way without the use of any special apparatus upon the avoidance of the previous preparaand without any diflicult treatment to obtain tion of the Schiff base by treating the matea practically quantitative yield of the desired rials for its formation with a solution of hynitriles. 75 drocyanic acid under conditions which are de- The following examples will serve to further fined in the said specifications. I have now illustrate the method by which I obtain the ni- 3 discovered that it is possible to prepare the triles. My invention, however, is notconfined nitriles from the Schiff bases themselves (both to these examples. The parts are by weight. of the fatty and of the aromatic series) with Ewcmple 1Prcparatz'0n of omega-cyrmcase and to obtain a good yield. The Schifi" methyl-amide.Seventy (70) parts of potasbases, which can be used according to my insium cyanid containing about ninety-five 35 vention, are both the monomolecular and the per cent. of KCN dissolved in two hundred polymolecular bases obtainable by condensing (200) parts of water and three hundred (300) together an aromatic amido compound and an parts of ice are placed in a vessel capable 8 5 aromatic aldehyde and also the polymolecular of withstanding pressure and provided with compounds which can be obtained by condensa stirrer, and to this is added the equiva- 4 ing together an aromatic amido compound and lent quantity of hydrochloric acid. To this an aliphatic aldehyde, and the acid nitriles obsolution, which contains about five 5) per tained according to my invention may be incent. of hydrocyanic acid, are added one hun- 9 dicated by the general formula dred and five parts of finely-powdered ON anhydro-formaldehyde-anilin, and the whole I 45 1s stirred at ordinary temperature till it be- H comes a homogeneous paste, whereupon the vessel is closed and heated for two (2) hours 95 in which the expression R indicates a radical in boiling water. After cooling the solidified paper.

nitrile can be easily filtered off from the aqueous solution. The reaction proceeds inasimilar manner when aethylidene-anilin is used instead of the anhydro-formaldehyde-anilin.

lia'ample 2Prepcmtion of p/wng Z-mii- Zz'cZo-acetonitodie.Ninety parts of henzylidene-anilin, two hundred (200) parts of crushed ice, and thirty-five (35) parts of potassium cyanid (containing about ninety-five per cent. of KCN) are stirred together in a vessel and sufficient hydrochloric acid is added until the mixture just reacts upon congo The vessel is then closed and heated for two (2) hours at atemperature of between one hundred and forty and one hundred and fifty degrees centigrade, (14:0 to 150 O.) After cooling the odor of hydrocyanic acid is scarcely recognizable. The dark crystalline mass is filtered off and after one (1) extraction with alcohol it is practically pure phenylanilido-acetonitrile.

Elmmplc 3PrqJ(0/*ati0n 0f omega-cymbmethyl-pamtoluicZ m.The anhydro base obtainable from one hundred and seven (107) parts of paratoluidin and seventy-nine ('79) parts of commercial aqueous formaldehyde solution containing about forty (40) per cent. of formaldehyde is finely powdered and introduced, together with five hundred and ten (510) parts of an aqueous solution of hydrocyanic acid containing about live and threetenths (5.3) per cent. of HON, into an autoclave provided with a stirrer. This is then heated for two (2) hours while stirring at a temperature of about eighty to one hundred degrees centigrade, (80 to C.) After cooling the nitrile is filtered off and pressed and dried. It possesses a melting-point of sixtytwo degrees centigrade, (62 O.)

and forty-three (1-13) parts of alpha-napththylamin and one hundred and six (106) parts of benzaldehyde are stirred well together while being heated on the water-bath. Hereupon water splits off and benzylidin-alpha-naphthylamin is formed, which after crystallization out of alcohol, melts at a temperature of from seventy-three to seventy-four degrees centigrade, (7 3 to 74 C.) This is finely powdered and heated together with six hundred and seventy-five (675) parts of an aqueous solution of hydrocyanic acid containing about four (4c) per cent. of HCN in an autoclave for about two (2) hours, while stirring, at a temperature of the boiling-bath. The nitrile obtained after being lightly washed with cold alcohol melts at a temperature of from one hundred and sixteen to one hundred and seventeen degrees centigrade, (116 to 117 O C.) Exactly the same procedure is followed to obtain the corresponding nitrile, which melts at a temperature of one hundred and fifteen degrees centigrade C) from benzylidin-beta-naphthylamin, melting-point about one hundred and twelve degrees centigrade, (112 G.)

Era mph 5-Prcpmutioa 0f omega-cyanort/w-cltlor-LcnzyZ-cm56in. One hundred and forty and a half (1 10.5) parts of ortho-chlor benzaldehyde and nine-three (93) partsof anilin are gently warmed together for a short time in an open autoclave, whereupon water splits off and the oily Sehiff base is formed. To this is added three hundred (300) parts of ethyl alcohol and two hundred and fifty (250) parts of an aqueous solution of hydrocyanic acid containing about eleven (11) per cent. of HUN. The vessel is then closed and the mixture is heated for two (2) hours while stirring at a temperature of about eighty to one hundred degrees centigrade, (80 to 100 C.) After cooling the greater part of the nitrile thus formed is already crystallized out. The remainder can be precipitated from the dilute alcoholic filtrate by the addition of water. The nitrile melts at a temperature of about seventy-seven degrees centigrade, ('77 0.)

Example 6-Prepmatimt of omega-cyanbmzyZ-mzt/mmilc accZ.The benzylidin-anthranilic acid of melting-point one hundred and thirty degrees centigrade (130 C.) obtainable from one hundred and thirty-seven (137) parts of dry anthranilic acid and one hundred and six (106) parts of benzaldehyde is mixed with three hundred (300) parts of methyl alcohol and five hundred and ten (510) parts of an aqueous solution of hydrocyanic acid containing five and three-tenths (5.3) per cent. of HON. The whole is then heated in an autoclave while well stirring at a temperature of from sixty to seventy-five degrees centigrade, (60 to 7 5 O.) The formation of the nitrile is completed after a short time. This omega-cyambenzyl-anthranilic acid melts at a lSGIXlPGIZLCLUB of one hundred and seventy-five degrees centigrade, (175 C.) In a similar manner the ethylidin-anthranilic acid, which is obtainable out of acetyl-aldehyde and anthranilic acid in the presence of water, can be converted into anthranilido-alpha-propio-nitrile, which melts at a temperature of about one hundred and ninety-two degrees centigrade, (192 C.)

I claim 1. The process for the manufacture of acid nitriles of the general formula CN R-NHCH RI where R and R represent aromatic hydrocarbon radicals, which process consists in heating a Schiff base with a solution of hydrocyanic acid.

2. The process for the manufacture of acid nitriles of the general formula CN R-NHCH I'IO which consists in heating a polymolecular Schiff base obtainable from an aromatic amin and an aliphatic aldehyde with a solution of hydrocyanic acid.

3. The process for the manufacture of acid nitriles of the general formula CN OGH5 NH OI I\ which consists in heating a polymolecular Schiff base obtainable from anilin and an aliwhich process consists in heating anhydroformaldehyde-anilin With a solution of hydrocyanic acid.

5. The process for the manufactureof an acid nitrile of the formula witnesses.

OTTO J. GRAUL. Witnesses:

J ACOB ADRIAN, J. ALuo LLOYD. 

